Aircraft



Oct. 26, 1937. w DYER ET AL 2,097,117

AIRCRAFT Filed July 26, 1935 2 Sheets-Sheet l Ill il.-- am V..

Fig. 3. 6

Oct. 26, 1937. w. DYER ET AL 2,097,117

' AIRCRAFT Filed July 26, 1935 2 Sheets-Sheet. 2

F ig. Z.y

27 ay I Patented` Oct. 26, 1937 UNITED sTA'rizsy PAVTENT oFF-lcsAIRCRAFT John wiuininpyer ana..,navia Kay, Edinburgh, Scotland,assignors to Kay=Gyroplanes Limited,

Edinburgh, Scotland Application July 26, 1935, serial No. 33,395 InGreat Britain July ,27, 1934 13.- ciainis. (ci. zii-18)' incidence. ofthe blades when in the forefand-.aft

'This invention relates'to aircraft of the kind in which the lift isderived wholly or partly from an overhead rotative wing system,confim'only.V

fore-and-aft direction to enable the direction of g ight to be changedfrom -the horizontal.

For this purpose, the rotor-has usuallybeen mounted' on a form of mastcapable of being swung in either a lateral or in a fore-and-aftdirection about its lower end.

It is found, however, that when the rotor is tilted laterally theeiective angle of incidence of any rotor bladewhich points in afore-andaft direction is varied and, moreover, that the direction ofsuch variation (i.`e., vWhether it operates to increase or decrease theeffective angle of incidence) is opposite according to whether the bladepoints in a fore or in an' aft 40 vention we provide in or for anaircraft of theV kind referred to, the combination of meansv for tiltingthe rotor laterally of the aircraft and automatically operating meansfor compensating for the variation in the effective angle of 45incidence of the rotor blade-or b1ades pointing in a fore-and-'aftdirection which is caused by the lateral tilting. More specifically Weprovide means for tilting the rotor laterally of the aircraft incombination with means for causing the 50 said lateral movement to bringabout asimultaneous fore-and-aft movement of the rotor.' Needless tosay, the direction of the fore-andaft movement thus obtained would besuch as to give the required compensation by maintaining 55Vthe properrelationship between the angles 4of In aircraft of this character it isalready positions respectively.

Expressed more specically, we provide a rotorsupporting member uponwhich the rotor is turnablymounted and means for -carrying the' saidmember in --sucha inanner that the member can be tilted laterally., andalso longitudinally of the aircraft, in combination with means for 1causing a simultaneous fore-and-iaft movement of the saidSupporting'member to take place when the means upon which the latter iscarried .is operated to tilt the rotor-supporting member laterally.

In a convenient construction, the vaircraft 'comprises a lrotor-carryingmast or the like which is pivotally mounted at its lower end forswinging movement either laterally or longi tudinally incombination-'with means which anchors the mast or the like to a xed partof the aircraft and .is connectedto the mast or the like ata positiondisplaced orloi-set froml both the longitudinal and transverse pivotalaxes of the mast or the like, the arrangement being such that thelateral tilting of the mast or the like takes place simultaneously witha foreand-aftmovem'ent of the latter. lThe fore-andaft inclination ofthe rotor can be varied either initially or whilst the aircraft is inflight under the control of the pilot independently of the actuation ofthe means producing lateral tilting of the rotor. n'

Invthe above construction the rotor-carrying mast or the like isprvided'at its lower end with a form of frame or ,bracket member orequivalent which is capable Tof rocking aboutits longitudinal axis (forlateral inclination'4 of. the rotor) and about its transverse axis (forforeand-aft inclination of the rotor) and the. means for anchoring themast or the like to the fixed part -of the aircraft consists of ananchoring link or the like, which is attached to the said frame orbracketv or equivalent in a position oiset rearwardly of thetransverseaxis and also laterally of the longitudinal axis.

A further feature of the invention consists in the possibility ofemploying for obtaining the lateral tiltingjmeans of the kind described'in the specification of Patent 1,750,778, granted to one ofthe presentapplicants, as being used for varying the angles of incidence ofairscrews, re.-A

. volving blades or wings, and propellers. Ac

like comprised two co-axial parts turnably arturnably mounted, the axisof the crank'pin member being inclined to theI common axis of thecoaxial parts.

With this arrangement (whichwe wish'to -beunderstood as including itsvarious modications) the blade is rotated substantially about itslongitudinal axis so as tovary its angle of incidence with its generalplane of rotation, and the plane in which the crank pin axis is inclinedwhen in its mid-position is the general plane of rotation. Incontra-distinction to this arrangement, inv adapting the device fortilting the rotor in accordance with the present invention, the plane inwhich the crank-pin axis is inclined when the rotor is in the normal -ormid-position intersects the axis of the mast, for instance, is at rightangles thereto.

It will be readily appreciated that by the use of an arrangement of thissort the mast, or the frame or equivalent carrying the same, can betilted laterally at will by rotating the co-axial parts of the crank-pinmember, whilst at the same time it is free to tilt about the axis ofsaid crank pin member (i. e., in a fore-and-aft direction).

In assembling the parts in an aircraft, it will be obvious that as thecrank-pin member or equivaient is inclined to the axis of its supportingparts, either the axis of the crank pin member or that of saidsupporting parts can be arranged at right angles to the centre line ofthe machine but, in practice, it is preferred, according to the Apresent invention, to adopt the second of these courses, since thelongitudinal tilting of the mast can then take place along a lineinclined to the centre line of the machine and consequently theunbalancing of the lift due to the variation in the angles of incidenceof any laterally extending blades will be compensated, at least to someextent, by the shifting of the rotor centre with respect to the centreof gravity of the aircraft.

A further feature of this invention consists in utilizing the aforesaidoffset anchoring link of the rotor mast as a means for altering the trimof the aircraft by varying the fore-and-aft inclination of the mast. Forthis purpose, said link may be attached at its lower end to anadjustable anchorage which is preferably adapted to be con-v trolledfrom the cockpit of the aircraft. Said adjustable anchorage may be ofany suitable form, but may conveniently comprise a bush or drum adaptedto afford a universal connection with the end of the,link, said bush ordrum being threaded into a convenient fixed part and rotated foradjustment by a cable connected to a control in the cockpit, or in anyother convenient manner.

One constructional form of the invention, applied to a rotor-supportingmast, carried on 'a hinge-pin or zed crank member, is hereinafterdescribed, by way of example only, with reference .to the accompanyingdrawings, whereonz- Fig. 1 is an elevation, partly in section, of partof the rotor construction and shows the method of mounting therotor-supporting mast for lateral and fore-and-aft tilting;

Fig. 2 is a plan view on the line C-C in Fig. 1;

Fig. 3 is a section looking aft on the line D-D in Fig. 2; and

Fig. 4 is an end elevation partly in section and looking forward on theline E-E in Fig. 2.

In a constructional embodiment of the invention, the hollow mast I onwhich the rotor I A turns is forked at its lower end to form twoparalle] arms 2 and 3 extending vertically downwards. Said arms arepivotally carried near their front ends by the crank-pin member orbarrel 5 of the Zed-crank device for effecting the lateral tilting ofthe mast I, and side cheeks 6 and I which are secured to the arms andextend rearwardly thereof are interconnected near their other ends by across-member 8 to which an an the parallel arms 2 and 3 and side cheeks6 and 'I being at right angles to the barrel, are in turn inclined tothe longitudinal centre line of the machine. 'I'he position of the mastI may be either vertically above or slightly behind the barrel 5, whilstthe side cheeks 6 and 'I extend for a relatively substantial distancerearwardly from the point at which the mast is mounted on the barrel tothat at which the anchoring link 9 is attached. It is preferred to mountthe mast so that its vertical axis lies between the barrel 5 and theanchoring link 9, since in this way the load is divided more equallybetween these two parts. This feature is also of importance infacilitating the carrying out of the invention described in ourcopending application relating to the adjustment of the angles ofincidence of the rotorbla'des. According to said co-pending application,the operating means of the incidencecontrol has its axis coincident withthe axis of rotation of the rotor, and, comprises, in one embodiment,lan actuating shaft II, see Fig. l, reciprocably mounted in the centreof the rotor mast I and coupled, as by lever and link mechanism, to theincidence-varying means. Clearly, it is desirable to leave anunobstructed space for the passage of said actuating shaft through therotor support and, for this reason, the two inventions are preferablyused in conjunction with each other. The reciprocation of the saidincidence-controllingshaft may, of course, be of a purely sliding naturebut in the preferred construction described it is mounted in threadedengagement with the rotor-carrying mast I so that rotation of the shaftin oneirection or the other will cause the simultaneous verticalreciprocation of the shaft in the mast.

The rotation of the said shaft is effected in any convenient manner froma control operated by the pilot e. g., by a continuous flexible cable lrunning over a grooved pulley I2 at the lower end of the shaft, whilsttelescopic and universal shaft.

An arrangement constructed in accordance with the present invention,withor without the arrangement of the incidence-control operating meansjust described, can also be usefully combined with the features of theinvention forming the subject of another of our co-pending applicationsrelating to the mounting of a pinion I3, Figs. 1 and 2, for transmittinga positive drive initially to the rotor hub IA. According to thatinvention, the pinion I3 is so mounted as to be capable of being swunginto or out of mesh with a gearwheel I4 associated with the rotor hub,and in one form is described as being eccentricaliy mounted in arotatable support I'I. In -combining that invention with the presentone, the pinion support or outer housing i5 is 'carried by the lowerends of the arms 2 and 3 of the rotor mast.- Thu's,

Il associated with the rotor hub IA, the pinion is described as beingcarried on the upper end of the spindle I6 rotatably mounted in ahousing I1 which in turn is rotatably mounted in the support I5 carriedby the arms 2 and 3. The spindle I6 is arranged slightly off-centre oreccentrically in the housing I1, so that upon the latter being rotatedthe pinion is swung through an arc of a circle having a radius equal tothe distance between its own axis and that of the support I5.

The rotation vof the support or inner hcusng I1 may be enected in anyconvenient manner by the pilot. For example, a cable may be attached toits lower end and led over pulleys or the like to an operating lever orwheel in the cockpit of the aircraft, or, alternatively, it may beoperated by gearing orby a suitable system of levers and 'I'heeccentricity. of the axis of rotation of the pinion I3 would be suchIthat when the pinion is driving the annulus Il, the reaction between theengaging teeth will tend to force the gears deeper into mesh and,conversely, when the rotor ls uncoupled from the power take-off shaft,it will tend to throw the pinion out of mesh with the gear on theannulus.

In addition to being offset rearwardly from the axisofthemast Itheanchoringlinkisalso onset laterally from the longitudinal centre lineB-B' about which lateral swinging of the mast I taires place. Upon theupper end of the link there is screwed a fork I8 to which a block` I9,slidable on the cross pin 8, is secured by means of a pin 20 passingthrough the fork and the shank of the said block. 'I'he block I9 is thusadjustable axially along the pin 8 so that the exe tent of its lateraloff-setting from the 'centre line B-B can be varied as required. In theconstruction shown, the block is housed between a washer 2I andadistance tube 22 bot-h of which can obviously be replaced by similarmembers of differentlengths to nx the-block in various positions on thepin 8, n the other hand, of course; it would be a matter of simplicityto arrange to vary the position. of the block on the pin 8 initially orduring flight by means under the control of the pilot, e. g., by forminga screw, thread on the pin 8 and twisting the latter by any convenientform of remote control from the cockpit.

To allow lateral swinging of the mast I to take place the link has aball 'and socket connection at its lower end with a control drum 23threaded into a -nut 24 fixed to and projecting through the base 25 ofthe structure 26 which carries the rotor and is mounted upon a pylonstructure (not shown) fixed to the fuselage of the aircraft.

Said drum is provided at its lower end with grooves 21, on which iswound a continuousilexible cable, the two ends of -which are attached toa suitable control member (in this instance, a hand wheel) in thecockpit or elsewhere. In this connection, the pitch of the grooves 21 inthe drum 23 is equal to and of the same hand as that of the adjustingthreads on the drum and in the nut 2l, so that the take-oir of the cablefrom the drum remains at a constant height, thus facilitating theguiding of the cable;

The rotation of the axle I0 of the crank-pin or barrel for effecting thelateral tilting of the mast I can be carried out in any'convenientmanner. For example, as shown in the drawings, it is carried out bymeans of a rotatable shaft 28 through worm gearing 29, the said shaftbeing operated manually in any suitable way or it may be power operated.As shown, it is operated by the provision of a grooved drum 30 on whichis wound an endless cable attached at its two ends to a control in thecockpit. On the other hand, in an alternative construction, the axle I0is turned by a control member pivotally arranged in the cockpit andcoupled to the axle by lever and link mechanism.

The operation is as follows:-

When the rotor is to be tilted, the axle I0 is turned through the abovevmentioned control. The axis of .the barrel 5 in the neutral position ofthe device lies in a horizontal or substantially horizontal plane and isobliquely disposed to the axis of the axle I0 which it intersects.Secondly, the effect of a rotation of the axle III can be regarded asproducing a movement of the barrel compounded of an oscillation about avertical axis through the point of intersection of the axis of the axleI0 and that of the barrel and about a horizontal axis passing throughthe same point, whereby if the rotor were to be held by any means frommoving in a fore and aft direction the effect of rotation of the barrelwould be to cause the rotor mast to tilt to either side and, since,`

the mast is offset rearwardly from the barrel, to swing bodilylaterally. If the bodily movement is disregarded, lateral tilting oftherotor mast in one direction will cause' one end of the pin B toapproachk the base 28 and the other end to recede from it. The link 9 bylimiting such movement causes Ithe mast to incline forwardly orrearwardly. as the case may be. as well as to tilt laterally. The partlylateral and partly fore and aft movement of the mast, therefore, isforwardy on one side and rearward on the other of a plane at rightangles to the axis B-B and passing through the axis of the mast.

The direction of the longitudinal movement of 'the mast for a givendirection of lateral movement of the same member' depends upon the po.sition of the anchoring link 9 and is reversed if the offsetting of saidlink is changed from right to left or vice versa o f the .axis B-B.

Actually, in the present case, in which the rotor revolvesanti-clockwise as seen from below and in which the axis about whichlongitudinal tilting takes place is-forward of the point of anchorage,the latter requires to be offset towards the port sided! the aircraft. 1

The longitudinal swinging of the mast is a purely pivotal movement aboutthe axis of the crank-pin member or barrel 5 and at right anglesthereto, and the fore-and-aft setting of the mast can be varied byturning the threaded drum 23 to which the anchoring link 9 is connected,as described. K

Inthe aircraft to which the specic construction above is applied,longitudinal control of the aircraft is effected in flight bythe use ofelevators pivoted tothe tailplane.

We claim:

l. In aircraft of the kind bladed rotor lfor lifting or assisting inlifting the craft, the combination of means for tilting the rotorlaterally of the aircraft with means for causing` the said lateralmovement to cause a simultaneous fore-and-aft movement of the rotor,Awhereby automatic compensation is obtained for maintaining the trim ofthe aircraft when the rotor is tilted laterally in either direction.

referred to having a bladed rotor for lifting or assisting in liftingthe craft, a rotor-carrying mast or the like pivotaily mounted. at itslower end for swinging movement either laterally or'longitudinally, in-oombination with means which anchors the mast or the like to a fixedpart of the aircraft and is'connected to I the mast or the like at aposition displaced .or off-set from both the longitudinal and transversepivotal ax'es of the mast 'or the like, the arrangement being-such thatthe lateral tilting of the mast or the like takes place simultaneouslywith a fore-and-aft movement of the latter.

3. In an aircraft as claimed in claim 2, wherein the fore-and-aftinclination of the rotor can be varied either initially or whilst theaircraft is in ight under the control of the pilot independently of theactuation of the means producing lateral tilting of the rotor. i y

4. In an aircraft ofthe kind described having I a bladed rotor forlifting or assisting in lifting the craft the combination of a rotorcarrying mast provided at its lower end with a support capable ofrocking about an axis extending in one direction, and also about an axisextending at substantially right angles to said axis, and meansanchoring the mast to a fixed part of the aircraft, said meanscomprising an anchoring linkA which is attached to said support in aposition onset laterally with respect to both of said axes about whichthe support rocks.

'5. In an aircraft of the type described, having a bladed rotor forlifting or ting in lifting the craft, the combination of a rotorcarrying mast provided at its lower end with a support, said supportbeing mounted to rock about an axis for giving the rotor inclinationlaterally of the craft and about another axis forgiving inclination tothe rotor substantially fore and aft of the craft, and means anchoringthe mast to a fixed part of the aircraft, said means comprising ananchoring link which is attached to said support in a position offsetrearwardly of the axis about which the fore and aft inclination is-givento the rotor and laterally of the axis about which the said lateralinclination to the rotor takes place.

6. In' an aircraft of the kind described having a bladed rotor forlifting or assisting in lifting the craft the' combination of a rotorcarrying mast provided at its lower end with a support capable ofrocking about an axis extending in one direction and also about an axisextending at substantially right angles to said axis, and meansanchoring the mast to a ilxed part of the aircraft, said meanscomprising an anchoring link which is attached to said support in aposition offset laterally with respect to both of said axes about whichthe support rocks, the arrangement being such that the lateral tiltingof the mast takes place simultaneously with the fore-and-aft movement ofthe latter.

7. In an aircraft of the kind in which the lift is derived wholly orpartly from an overhead rotative wing system or rotor, the combinationcomprising a rotor-carrying mast or the like, pivotally mounted at itslower end for tilting movement either laterally or longitudinally, andmean; anchoring said mast to a fixed part of the aircraft connected tothe mast at a position dis-- placed or off-set from both thelongitudinal and transverse pivotal axes of the mast or the like, thearrangement being such that the lateral tilting oi' the mast, takesplace simultaneously` with a fore-and-aft movement of the latter. `l 8.A device as claimed in claim 7, whereinthe mast is mounted for lateraland longitudinal tilting on the crank-pin or equivalent member of ahinge-pin or zed-crank member, the axis of the crank-pin or equivalentmember being inclined to the axis of the co-axial bearing Darts of thehinge-pin or Zed-crank member.

9. A device as claimed in claim 6, wherein the lower end of theanchoring link or the like is universally jointed to a member which ismounted upon and is adjustable relatively to a structure supported bythe fuselage and acting to carry the rotor system, said member beingcontrollable to alter the fore-and-aft inclination of the rotorcarryingmast either initially or during flight under control of the pilot.

l0. A device as claimed in claim 6, wherein the lower end of theanchoring link or the like is universally jointed to a drum, whichisscrewthreaded into a nut member secured to the aircraft structure, andthe said drum is operatively connected to a control arranged in acockpit of the aircraft.

1l. A device as claimed in claim 6, wherein the lower end of theanchoring link or the like is universally jointed to a grooved drumwhich is screw-threaded into a nut member secured to the aircraftstructure, andsaid grooved drum is operatively connected by means of acable to a control arranged in the cockpit of the aircraft, the pitch ofthe grooves in said drum being equal to and of the same hand as that ofthe cooperating screw-threads on the drum and nut so that the take-on ofthe cable from the drum remains at a constant height.

12. A device as claimed in claim 7, wherein the rotor carrying mast .ispivotally mounted at its lower endy for tilting movement eitherlaterally or longitudinally on the crank-pin or equivalent member of ahinge-pin or Zed-crank member, which latter member has co-axial bearingparts arranged at right angles to the longitudinal axis of the aircraft.

13. An aircraft in which the lift is derived wholly or partly from anoverhead rotative wing system or rotor, comprising in combination meansfor tilting the rotor laterally of the aircraft and means adapted toprovide automatic compensation for maintaining the trim of the ment ofthe rotor.

JOHN WILLIAM DYER. DAVID KAY. v

